No, I don't use it, but when I turned it on just now, it did make me feel like it would be easier to deal with multiple panels. If that's something that gets people interested initially -- that is, if it's a feature that helps new users -- it might be important in converting new users to paying customers. Chrome generally helps new users but hinders power users.

If you were to remove it, I think you could consider promoting the existing functionality to something more prominent. It's hidden a little under View | Layout. Consider promiting View | Layout to a traditional "Window" root menu; use the icons on the toolbar as the icons on the menu items, so the user can visually select the format they're interested in. That way the rather neat feature isn't buried.